Watching Netflix requires Microsoft Silverlight which isn't available in Linux. Here comes an unofficial Netflix app for Ubuntu which makes it easy to install Netflix and start watching movies right away. The app is using WINE and can be easily installed through a PPA created by Erich Hoover. Just open a terminal and type:

Once installed, go up to the top left of your screen and open your Unity dash, search for Netflix and run the app. It will load up everything needed on the first run. After logging into your Netflix account and selecting a video to play, Silverlight should ask you to enable DRM content. Please enable it. Netflix movies should work fine now!

The Netflix app starts in full screen mode. You can exit out of the app completely by pressing ALT+F4. You can also press F11 to exit full screen mode.